TW201343287A - Release film for producing green sheet - Google Patents

Abstract

The present invention provides a release film for producing green sheet. The release film includes a base, a release agent layer, and a back coat layer. The release layer is formed by applying and curing a material, containing a first active energy ray curable compound and a first polyorganosiloxane, onto the first surface of the base. The back coat layer is formed by applying and curing a material, containing a second active energy ray curable compound, onto the second surface of the base. An outer surface of the release agent layer has average roughness of 8 nm or less and maximum profile peak of 50 nm or lower. An outer surface of the back coat layer has average roughness of 5 to 40 nm and maximum profile peak of 60 to 500 nm. According to the present invention, it is possible to prevent pinholes and thickness variation from occurring to the green sheet.

Description

Release film for the production of green sheets

The present invention relates to a release film for producing green sheets.

The production of laminated ceramic capacitors requires the use of green sheets, which are used to make such green sheets.

Usually, a component for producing a green sheet of a green sheet (referred to as a release film) has a substrate and a release agent layer. When the green embryo is produced, the ceramic particles and the adhesive resin are first dispersed in an organic solvent, and the ceramic slurry is applied to the release film, and the coating is dried to become a green sheet. This manufacturing method enables efficient production of a green sheet having a uniform thickness. The green sheet thus produced can be used for the manufacture of a laminated ceramic capacitor after being released from the release film.

In the production process of the green sheet, the release film formed after the green sheet is generally stored and transported in a state of being wound up.

Since the surface roughness (ie, the average roughness value) of the substrate of the release film on the opposite side (ie, the back surface) of the release agent layer is high, when the release film is stored in the wound state, the release film is removed. A defect such as a condition (for example, clogging) in which a substrate is attached to a surface on which a release agent layer is to be produced (that is, a front surface) and a back surface. These defects are being attempted to be solved (for example, Patent Document 1, Japanese Patent Laid-Open Publication No. 2003-203822).

However, when the release film described in Patent Document 1 is used, when the release film after the formation of the green sheet is taken up and stored, the shape of the back surface of the release film is still transferred to the produced green sheet. On the sheet, sometimes the green sheet is partially thinned. This can cause a short circuit in the laminated ceramic capacitor produced by the accumulation of these green sheets.

On the other hand, if the surface roughness of the opposite surface of the surface on which the release agent layer is to be produced on the substrate is relatively small, the front surface is particularly smooth. At this time, the slipperiness of the front surface and the back surface of the release film may be deteriorated, resulting in defects such as poor shrinkage or clogging.

An object of the present invention is to provide a release film which can prevent the problem that the produced green sheets are small pores or uneven in thickness.

The release film has a substrate, a release agent layer, and a bottom coat layer. The substrate has a first side and a second side. The release agent layer is formed after the active energy ray is irradiated to cure the release agent coating layer. The release agent coating layer is formed by applying a raw material for forming a release agent layer onto the first surface of the substrate. The raw material for forming a release agent layer contains the first active energy ray curable compound (a1) and the first polyorganosiloxane (b1). The undercoat layer is formed by the active energy ray irradiation curing the undercoat layer. The undercoat layer is formed by applying a raw material for forming a bottom coat layer on the second surface of the substrate. The raw material for forming the undercoat layer contains the second active energy ray curable compound (a2). The outer surface of the release agent layer has an average roughness Ra ₂ of 8 nm or less, and the outer surface of the release agent layer has a maximum protrusion height Rp ₂ of 50 nm or less. The outer surface of the undercoat layer has an average roughness Ra _{3 of} between 5 nm and 40 nm, and the outer surface of the undercoat layer has a maximum protrusion height Rp _{3 of} between 60 nm and 500 nm.

In the above release film, the raw material for forming the undercoat layer may further contain the second polyorganosiloxane (b2).

Therefore, the present invention can prevent the problem that the produced green sheets are small pores or uneven in thickness. Further, the outer surface of the formed release film has high smoothness and excellent release property.

1‧‧‧ release film

11‧‧‧Substrate

111‧‧‧The first side of the substrate

112‧‧‧ second side of the substrate

12‧‧‧ release agent layer

121‧‧‧The outer surface of the release agent layer 12

13‧‧‧Bottom coating

131‧‧‧The outer surface of the undercoat layer 13

Figure 1 is a cross-sectional view of a release film in accordance with an embodiment of the present invention.

The following is a detailed description of one embodiment of the present invention.

(release film)

The release film of the present invention is a release film for the production of green sheets.

Fig. 1 is a cross-sectional view showing a release film according to an embodiment of the present invention.

As shown in FIG. 1, the release film 1 includes a substrate 11, a release agent layer 12 on the first face 111 of the substrate 11, and a bottom coat layer 13 on the second face 112 of the substrate 11.

The release film 1 of the present invention has a substrate 11, a release agent layer 12, and a bottom coat layer 13. The substrate 11 has a first surface 111 and a second surface 112. The release agent layer 12 is formed after the active energy ray is irradiated to cure the release agent coating layer. The release agent coating layer is formed by applying a release agent layer forming material onto the first surface 111 of the substrate 11. The raw material for forming a release agent layer contains the first active energy ray curable compound (a1) and the first polyorganosiloxane (b1). The undercoat layer 13 is formed by irradiating the cured undercoat layer with active energy rays. The undercoat layer is formed by applying a raw material for forming a bottom coat layer onto the second surface 112 of the substrate 11. The raw material for forming the undercoat layer contains the second active energy ray curable compound (a2). The outer surface 121 of the release agent layer 12 has an average roughness Ra ₂ of 8 nm or less, and the outer surface 121 of the release agent layer 12 has a maximum protrusion height Rp ₂ of 50 nm or less. The outer surface 131 of the undercoat layer 13 has an average roughness Ra _{3 of} between 5 nm and 40 nm, and the outer surface 131 of the undercoat layer 13 has a maximum protrusion height Rp _{3 of} between 60 nm and 500 nm. .

Since the outer surface 121 of the release agent layer 12 is smoother than the outer surface 131 of the undercoat layer 13, the depression on the green sheet due to the protrusion of the outer surface 121 of the release agent layer 12 (ie, The projections (i.e., the projections) formed by the projection of the outer surface 131 of the undercoat layer 13 will have a matching portion, and thus it is possible to prevent the green sheets from generating small holes.

The release film 1 of the present invention is characterized in that the green sheet is not directly in contact with the substrate 11 in use, so that the rough surface shape on the substrate 11 will not be transferred onto the green sheet. Therefore, it is possible to prevent small holes or uneven thickness from occurring on the green sheet, and to produce a good green sheet. Especially if even The thickness of the embryonic sheet is extremely thin (for example, a thickness of 5 μm or less, particularly a thickness of 0.5 μm to 2 μm), and a good green sheet having no such defects can still be completed.

Further, as described above, the outer surface 121 of the release agent layer 12 of the release film 1 of the present invention has high smoothness and excellent release property. Therefore, it can be used to manufacture a good green sheet.

Further, since the release agent layer 12 and the undercoat layer 13 are used as the above-mentioned forming raw materials, the electrical properties of the release agent layer 12 and the undercoat layer 13 will be similar. This will prevent static electricity which may be generated when the release film 1 is turned over. Therefore, it is possible to prevent generation of small particles and small pores due to dust adhering due to generation of static electricity when the ceramic slurry is applied.

The following is a detailed description of the layers constituting the release film 1 in the present embodiment.

<Substrate>

The substrate 11 has a first surface 111 and a second surface 112.

The substrate 11 is a portion containing a physical function such as strength and elasticity in the release film 1.

The substrate 11 is not particularly limited in material, and suitable materials known to date can be selected. For example, polyester materials such as polyethylene terephthalate and polyethylene naphthalate, polyolefin materials such as polypropylene and polymethylpentene, and plastics such as polycarbonate. Films made of materials can be used. The substrate 11 may be a single layer, or may be two or more layers of the same type or not The same kind of material. Among these materials, a film of a polyester material is more preferable, in particular, a film formed of poly(p-ethylene glycol phthalate), and a film formed by biaxially stretching poly(p-ethylene glycol phthalate). Better. The purpose of using a plastic material is to prevent dust during processing and use, for example, to effectively prevent coating of ceramic slurry due to dust.

The average roughness Ra ₁ of the first face 111 of the substrate 11 is preferably between 2 nm and 80 nm, more preferably between 5 nm and 50 nm. As described later in the specification, the concave portion space on the first surface 111 of the substrate 11 and the projections of the convex portion are filled with each other, whereby a smooth release agent layer 12 can be produced. The average roughness Ra ₁ within the above range enables the smoothing effect to be more remarkable.

Further, the maximum protrusion height Rp ₁ of the first surface 111 of the substrate 11 is preferably between 10 nm and 700 nm, more preferably between 20 nm and 500 nm. As described later in the specification, the concave portion space on the first surface 111 of the substrate 11 and the projections of the convex portion are filled with each other, whereby a smooth release agent layer 12 can be produced. When the maximum protrusion height Rp _{1 is} within the above range, the smoothing effect is more remarkable.

The second surface of the substrate 112 average roughness value Ra ₀ 11 interposed between preferably 10 nm to 200 nm, is between 15 to 100 nm is more preferred. The undercoat layer 13 is produced on the second side 112 of the substrate 11 as will be described later in the specification. When the average roughness Ra _{0 is} within the above range, the average roughness Ra3 of the outer surface layer 131 of the undercoat layer is relatively easily adjusted.

The maximum protrusion height Rp ₀ of the second face 112 of the substrate 11 is preferably between 80 nm and 1000 nm, more preferably between 100 nm and 800 nm. The undercoat layer 13 can be produced on the second side 112 of the substrate 11 as follows. Within the above range enables the maximum projection height Rp ₀ outer layer 13 coating the bottom surface 131 of the maximum projection height Rp ₃ is easy to adjust.

The average thickness of the substrate 11 is preferably between 10 micrometers and 300 micrometers, more preferably between 15 micrometers and 200 micrometers. The average thickness in this range allows the release film 1 to have both appropriate elasticity and excellent tear resistance and crack resistance.

<release agent layer>

The release agent layer 12 is attached to the first face 111 of the substrate 11.

The release agent layer 12 allows the release film 1 to have a release property.

The release agent layer 12 is a product which is cured by the active energy ray after the raw material for forming a release agent layer containing a predetermined component is cured.

The raw material for forming a release agent layer contains the first active energy ray curable compound (a1) and the first polyorganosiloxane (b1).

The use of such a raw material for forming a release agent layer enables the release agent layer 12 after formation to have excellent curability and green sheet release property.

The following is a detailed description of each component.

[First active energy ray curable compound (a1)]

The first active energy ray curable compound (a1) is one of components which are cured into the release agent layer 12.

The first active energy ray curable compound (a1) is one molecule A compound containing two or more (preferably three or more) reactive functional groups described below is preferred. The reactive functional groups used may be selected from the group consisting of (meth)propenyl, alkenyl and maleimide. This gives excellent curability, solvent resistance and release properties. Further, examples of the alkenyl group include a vinyl group, an allyl group, and an allyl group having a carbon number of from 2 to 10.

Further, the content of the reactive functional group selected for the (di)acryloyl group, the alkenyl group and the maleimide of the first active energy ray curable compound (a1) should be 1 kg of the first activity. The ratio of the ray curable compound (a1) to 10 times or more is preferred. Thus, even if the raw material for forming a release agent layer is applied thinly on the first surface 111, the curability of the first active energy ray curable compound (a1) can be maintained in an excellent state.

The first active energy ray curable compound (a1) may be derived from diisopentaerythritol (di)triacrylate, diisopentaerythritol (di)tetraacrylate, diisoamyltetraol (m-)pentaacrylate, and A polyfunctional (meta) triacrylate such as pentaerythritol (inter)hexaacrylate, pentaerythritol (di)triacrylate or pentaerythritol (di)tetraacrylate is selected. From this, diisoamyl alcohol triacrylate, diisopentaerythritol tetraacrylate, diisopentyl alcohol pentaacrylate, diisopentyl alcohol hexaacrylate, pentaerythritol triacrylate, isoprene It is preferred to use at least one polyfunctional triacrylate in the tetraol tetraacrylate group.

In the component of the raw material for forming a release agent layer, the solid content of the first active energy ray curable compound (a1) (the ratio of the total solids after solvent removal) is 65 to 95.5% by mass. Good, quality Between 71% and 96.3 percent is better.

The active energy ray may be selected from a particle beam such as an infrared wave, a visible light, an ultraviolet ray, an X-ray electromagnetic wave, an electron beam, an ion beam, a neutron beam, or an alpha beam. Among the above examples, it is preferred to use ultraviolet rays, which makes it easier to form the release agent layer 12.

[First polyorganooxane (b1)]

The first polyorganosiloxane (b1) is a component which gives the release agent layer 12 a release function.

The first polyorganosiloxane (b1) can be selected, for example, from a polyorganosiloxane containing a linear or branched molecular chain. In particular, the terminal of the molecular chain or the branch of the molecular chain is a reactive functional group containing at least one reactive group of (meth)acryloyl, alkenyl or maleimide groups, by direct or divalent linkage. A denatured polyorganosiloxane having a ruthenium atom bonded to a molecular chain is preferred. Further, examples of the alkenyl group include a vinyl group, an allyl group, and an allyl group having a carbon number of from 2 to 10. The above-mentioned divalent linking group may be selected, for example, from a combination of an alkylene group, an oxyalkylene group, an oxy group, an imido group, and a valent group having a carbonyl group or higher. Further, the first polyorganosiloxane (b1) may be used in combination of two or more kinds as needed.

The denatured polyorganosiloxane which is substituted with a reactive functional group as described above is fixed to a bridge structure to the first active energy ray curable compound when the first active energy ray curable compound (a1) is cured by active energy ray irradiation. On the cured product of (a1). This prevents the aggregation of one of the components of the release agent layer 12 The organic decane is transferred or attached to the green sheet formed on the outer surface 121 of the release agent layer 12.

Further, the organic group other than the reactive functional group constituting the first polyorganosiloxane (b1) may be selected from monovalent hydrocarbon groups which do not contain an unsaturated aliphatic chain. The organic group may contain a plurality of hydrocarbon groups, or may be the same or different types from each other. The hydrocarbon group preferably has a carbon number of from 1 to 12, and more preferably a carbon number of from 1 to 10. Specifically, an alkyl group such as a methyl group, an ethyl group or a propyl group may be selected from an aryl group such as a phenyl group or a tolyl group.

In particular, the organic group other than the reactive functional group constituting the first polyorganosiloxane (b1) is preferably contained in an amount of 80 mol or more. This will make the release property of the release agent layer 12 particularly excellent.

The content of the first polyorganosiloxane (b1) in the raw material for forming a release agent layer is preferably 0.5% by mass to 55% by mass, wherein the mass is 0.7% by mass to 100% by mass. 4 is better. This allows the ceramic coating agent to be applied to the substrate 11 without causing repulsion, thereby producing the release film 1 excellent in release property.

On the other hand, if the content of the first polyorganosiloxane (b1) in the raw material for forming a release agent layer is less than the above lower limit, the release agent layer 12 formed may not fully exhibit its release property. On the other hand, if the content of the first polyorganosiloxane (b1) in the raw material for forming a release agent layer exceeds the above upper limit, the ceramic coating agent is applied to the surface of the formed release agent layer 12 when the ceramic coating agent is applied. There will be a possibility of repulsion. Also, the release agent layer 12 will be difficult to cure, And sometimes it is impossible to achieve complete release.

The mixing ratio of the first active energy ray curable compound (a1) is A% by mass, and the mixing ratio of the first polyorganosiloxane (b1) is B% by mass. The mass ratio B/A is preferably in the range of 0.7/99.3 to 5/95, and more preferably in the range of 1/99 to 4.5/95.5. This can make the above effects more remarkable.

[First photopolymerization initiator (c1)]

When ultraviolet rays are used as the active energy ray for curing the raw material for forming a release agent layer, the raw material for forming a release agent layer may contain a first photopolymerization initiator (c1).

The component of the first photopolymerization initiator (c1) is not particularly limited, but an α -aminoalkylphenol system is preferably used. Such an α -aminoalkylphenol-based photopolymerization initiator enables the first active energy ray curable compound (a1) to be less susceptible to oxygen suppression upon curing. This enables the release film 1 produced under normal air pressure to have excellent curability.

The α -aminoalkylphenol-based photopolymerization initiator may be 2-methyl-1[4-(methylthio)phenyl]-2-morpholinyl-1-propanone, 2-benzyl-2-di Methylamino-1-(4-morpholinylphenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4 -(4-morpholinyl)phenyl]1-butanone or the like is selected. This gives excellent curability, solvent resistance and release properties.

The solid content of the second photopolymerization initiator (c1) in the raw material for forming a release agent layer is preferably 1% by mass to 20% by mass, It is better to use 3 percent of the mass to 15 percent of the mass. Thus, even when the thickness of the release agent layer 12 is so thick that it is difficult to cure by oxygen suppression, excellent curability, solvent resistance, and release property can be maintained.

Further, in the vicinity of the outer surface 121 of the release agent layer 12 of the release film 1, there is a phenomenon in which the components of the first polyorganosiloxane (b1) are separated. The reason for this separation is considered to be because the first polyorganosiloxane (b1) used and the first active energy ray curable compound (a1) have different molecular structures, polarities, molecular masses, etc., and The oxane is caused by pushing up to the vicinity of the surface when the release coating layer is cured.

Further, the raw material for forming a release agent layer may contain other components in addition to the above components. For example, a sensitizer, a charge prevention agent, a curing agent, a reactive monomer, or the like may be contained.

As the sensitizer, for example, 2,4-diethylthioxanthone or isopropylthioxanthone can be used. This will give you a higher sensitivity.

The solid content of the other components in the raw material for forming the release agent layer is preferably from 0% by weight to 10% of the total mass.

The outer surface 121 of the release agent layer 12 has an average roughness Ra2 of 8 nm or less. This can effectively prevent the problem that small holes or uneven thickness are generated when the green sheet is formed on the outer surface 121 of the release agent layer 12. Thus, a smooth green sheet can be produced.

The maximum protrusion height Rp2 on the outer surface 121 of the release agent layer 12 is 50 nm or less. This can effectively prevent the green sheet from being deposited on the release layer 12 When the outer surface 121 is formed, problems such as occurrence of small holes or uneven thickness can be produced, and thus a green sheet having a smooth surface can be produced.

The area of the protrusion on the outer surface 121 of the release agent layer 12 having a height of more than 10 nm or more occupies 10% or less of the total area. This can effectively prevent the problem that small holes or uneven thickness are generated when the green sheet is formed on the outer surface 121 of the release agent layer 12, thereby producing a smooth surface of the green sheet.

The release agent layer 12 preferably has an average thickness of between 0.3 micrometers and 2 micrometers, and more preferably between 0.5 micrometers and 1.5 micrometers. If the thickness of the release agent layer 12 is less than the above lower limit, the outer surface 121 of the release agent layer 12 formed will not fully achieve the best smoothness. This causes a problem that small holes or uneven thickness may occur when the green sheet is formed on the outer surface 121 of the release agent layer 12. On the other hand, when the thickness of the release agent layer 12 is higher than the above upper limit, the release film 1 is likely to be curled by the curing shrinkage of the release agent layer 12. Further, there is a problem that clogging easily occurs between the substrate 11 and the release agent layer 12. This causes a problem that the release film 1 is defective in winding, and the possibility that the charge amount increases when the release film 1 is taken out.

<bottom coating>

The bottom coating 13 is located on the second side 112 of the substrate 11.

The undercoat layer 13 is formed in order to prevent the second surface 112 having a rough surface shape on the substrate 11 from directly contacting the green sheet, thereby preventing the occurrence of pinholes or uneven thickness of the green sheet.

And, the bottom coating 13 is for the second active energy shot The coating layer formed by coating the undercoat layer forming material of the line curable compound (a2) on the second surface 112 of the substrate 11 is formed by being irradiated with an active energy ray and then cured. This is to enable the undercoat layer 13 to have a smoother outer surface 131 and to generate static electricity when the release film 1 is prevented from being turned over.

[Second active energy ray curable compound (a2)]

As the second active energy ray curable compound (a2), for example, the same compound as described in the description section of the above first active energy ray curable compound (a1) can be used.

Further, the second active energy ray curable compound (a2) is preferably the same compound as the first active energy ray curable compound (a1). This can effectively prevent static electricity that may be generated when the release film 1 is turned over.

The composition of the raw material for forming the undercoat layer, the solid content of the second active energy ray curable compound (a2) (the proportion of the total solids after removing the solvent) is 65 to 100 percent of the total mass The best is between 65 and 98.5 percent of the total mass, and between 71 and 97 percent of the total mass is exceptional.

[Second polyorganooxane (b2)]

The raw material for forming the undercoat layer may contain a second polyorganosiloxane (b2).

As the second polyorganosiloxane (b2), for example, the same compound as described in the above description of the first polyorganosiloxane (b1) can be used.

This can prevent the laminated body formed by the green sheet on the release agent layer 12 of the release film 1 from being removed by crimping, and the laminated body taken out by crimping The green sheet is in contact with the undercoat layer 13 to cause the undercoat layer 13 to adhere to the green sheet.

The solid content of the second polyorganosiloxane (b2) in the raw material for forming the undercoat layer is preferably from 0 to 5 percent of the total mass, and from 0.5 to 4 percent of the total mass. The better between.

[Second photopolymerization initiator (c2)]

When ultraviolet rays are used to cure the active energy ray of the raw material for forming the undercoat layer, the raw material for forming the undercoat layer may contain a second photopolymerization initiator (c2).

As the second photopolymerization initiator (c2), for example, the same compound as described in the description section of the above first photopolymerization initiator (c1) can be used.

The solid content of the second photopolymerization initiator (c2) in the raw material for forming the undercoat layer is preferably 1% by mass to 20% by mass, and further 3 to 3% by mass. 15 percent is better. Thus, even when the thickness of the release agent layer 12 is so thick that it is difficult to cure due to oxygen suppression, excellent curability, solvent resistance, and release property can be maintained.

Further, the raw material for forming the undercoat layer may contain other components in addition to the above components. For example, a sensitizer, a charge prevention agent, a curing agent, a reactive monomer, or the like may be contained.

The solid content of the other components in the raw material for forming the undercoat layer is preferably from 0% by weight to 10% of the total mass.

The outer surface 131 of the undercoat layer 13 has an average roughness Ra3 of between 5 nm and 40 nm, preferably between 10 nm and 30 nm. This It is possible to effectively prevent the problem that small holes or uneven thickness are generated when the green sheet is formed on the outer surface 131 of the undercoat layer 13. Thus, a smooth green sheet can be produced. In addition, this also effectively prevents the occurrence of curling of the release film 1 when it is unwound. In this way, high tension is not required when rolling out, and core deformation due to curling can be suppressed.

The maximum protrusion height Rp3 on the outer surface 131 of the undercoat layer 13 is between 60 nm and 500 nm, and preferably between 80 nm and 400 nm, and between 100 nm and 300 nm. It is especially good. This enables the outer surface 121 of the release agent layer 12 to have a high degree of smoothness, so that the release film 1 needs to be wound with a waterproof material such as paper, plastic, or metal to achieve good airtightness, thereby being effective. Prevent roll-up conditions. In this way, high tension is not required when rolling out, and core deformation due to curling can be suppressed. Further, the clogging of the front side and the back side of the curled release film 1 can also be prevented. Further, it is also possible to prevent the surface shape of the outer surface 131 of the undercoat layer 13 bonded to the green sheet to be transferred onto the green sheet when the release film 1 in which the green sheet is produced is stored. It is effective in preventing the occurrence of small holes or uneven thickness of the green sheet, and thus it is possible to produce a raw sheet having a smooth surface.

The average thickness of the undercoat layer 13 is preferably between 0.01 micrometers and 2 micrometers, and more preferably between 0.05 micrometers and 1.5 micrometers. When the thickness of the undercoat layer 13 is less than the above upper limit, it is possible to prevent the release film 1 from being curled by the curing shrinkage of the undercoat layer 13. Moreover, the problem of clogging between the substrate 11 and the undercoat layer 13 causes a problem that the release film 1 is defective in winding. Being prevented. Further, if the thickness of the undercoat layer is higher than the above lower limit, the problem of an increase in the amount of charge at the time of taking out the release film 1 can be prevented.

(Method of manufacturing release film)

Next, a preferred embodiment of the method for producing the release film 1 will be described.

The present embodiment includes a first process of preparing the substrate 11, a second process of forming the release agent layer 12 on the first surface 111 of the substrate 11, and forming a bottom coating 13 on the second surface 112 of the substrate 11. A third project.

The following is a detailed introduction to each project.

<First Project>

This project will prepare the substrate 11.

The first surface 111 of the substrate 11 is surface-treated by an oxidation method. This will give the substrate 11 excellent adhesion to the release agent layer 12 formed on the first face 111 of the substrate 11.

Further, the oxidation method may be selected, for example, corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), fire treatment, hot air treatment, ozone treatment, ultraviolet treatment, and the like. Among these various treatment methods, they are selected in accordance with the type of the substrate 11. Corona discharge treatment is generally preferred because of its effectiveness and operability considerations.

<Second Project>

This process forms a release agent layer 12 on the first surface 111 of the substrate 11.

Specifically, first, a raw material for forming a release agent layer is applied to the base. The first side 111 of the panel 11 is dried and formed into a release agent coating layer. Between the coating process and the drying process, the concave and convex recessed space on the first surface 111 of the substrate 11 is filled with the projections of the convex portion, and the release agent layer 12 can be smoothly generated.

Next, the release agent coating layer is irradiated with active energy rays to form a smooth release agent layer 12 in accordance with the degree of curing. If the active energy ray is ultraviolet light, the amount of base light of the irradiation amount is preferably between 50 millijoules per square centimeter (mJ/cm ² ) and 1000 mJ/cm ² , and is between 100 mJ/cm ² and 500 mJ. Between /cm ² is better. Further, if the active energy ray is an electron beam, the irradiation amount of the electron beam is preferably between 0.1 kGy and 50 kGy.

A coating method for forming a raw material for forming a release layer can be used, for example, a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a knife coating method, a spin coating method, a die coating method, or the like. .

The raw material for forming a release agent layer is obtained by dissolving or dispersing a component of the first active energy ray curable compound (a1) and a first polyorganosiloxane (b1) which can be bonded thereto in a solvent.

As the solvent, for example, methanol, ethanol, toluene, ethyl acetate, xylene, methyl ethyl ketone, methyl ketone, isopropyl alcohol or the like can be used.

<Third Project>

This process forms a bottom coat layer 13 on the second surface 113 of the substrate 11.

The second side 112 of the substrate 11 can be surface treated by the same oxidation treatment as the first side. This allows the substrate 11 to have excellent adhesion to the undercoat layer 13 formed on the second surface 112 of the substrate 11.

Specifically, first, a raw material for forming a base coat layer is applied onto the second surface 112 of the substrate 11 and dried to form a bottom coat layer.

Next, the undercoat layer is irradiated with active energy rays to form a smooth undercoat layer 13 in accordance with the degree of solidification. The release film 1 is thus completed. If the active energy ray is ultraviolet light, the amount of base light of the irradiation amount is preferably between 50 mJ/cm ² and 1000 mJ/cm ² , and more preferably between 100 mJ/cm ² and 500 mJ/cm ² . good. Further, if the active energy ray is an electron beam, the irradiation amount of the electron beam is preferably between 0.1 kGy and 50 kGy.

As the coating method of the raw material for forming the undercoat layer, the same coating method as described in the second project can be used.

The raw material for forming the undercoat layer is obtained by dissolving or dispersing a component such as the second active energy ray curable compound (a2) in a solvent.

The solvent may be selected from the same solvents as those described in the second work.

Further, in the above description, the third project is performed after the completion of the second project, but the present invention is not limited thereto, and the third project may be performed first and then the second project may be performed, and the second project and the third project may be simultaneously performed.

According to the above construction, the release film 1 capable of producing a green sheet which can avoid problems such as small holes and uneven thickness can be obtained.

While the invention has been described above in the foregoing embodiments, it is not intended to limit the invention.

For example, in the above embodiment, the substrate 11 is constituted by a laminate produced by one layer. But it is not limited to this, for example, it is not limited to One layer may also be composed of a laminate of two or more layers. When the substrate 11 is a laminate, the outer layer closest to the release agent layer 12 during lamination may be a layer for adhesion adhesion to the release agent layer 12.

Further, when the substrate 11 is a laminate, the outer layer closest to the undercoat layer 13 during lamination may be a layer for adhesion to the undercoat layer 13.

Further, the method for producing the release film 1 of the present invention is not limited to the above method, and any work may be added as needed.

Next, a specific embodiment of the release film of the present invention will be explained.

[1] Preparation of release film 1

(Example 1)

First, the substrate 11 is selected from a film formed by biaxially stretching poly(p-ethylene glycol phthalate) [thickness: 38 μm, average roughness Ra _{1 of the} first side 111: 42 nm, maximum of the first side 111 The protrusion height Rp ₁ : 619 nm, the average roughness value Ra _{2 of the} second surface 112 : 42 nm, and the maximum protrusion height Rp _{2 of the} second surface 112 : 619 nm].

Next, the first active energy ray curable compound (a1) is selected from 94 parts by mass of diisopentaerythritol hexaacrylate (which accounts for the total mass% of the solid). The first polyorganosiloxane (b1) is selected from the group consisting of polydimethyl methacrylate containing a polyether-modified acryl oxime [manufactured by BYK Chemical Co., Ltd., and the product name is "BYK-3500", which is a percentage of the total mass of the solid. ] 1 part by mass. The first photopolymerization initiator (c1) is an α -aminoalkylphenol-based photopolymerization initiator (manufactured by BASF Corporation, under the product name "IRGACURE907", 2-methyl-1 [4-(methylthio)). Phenyl]-2-morpholinylpropan-1-one, 5 parts by mass based on the total mass of the solid. The above is dissolved in an isopropanol/methyl ethyl ketone mixed solvent (mass ratio: 3/1) and diluted to a solid content of 20% by mass to obtain a raw material for forming a release agent layer.

Next, a release agent for forming a release agent layer is applied onto the first surface 111 of the substrate 11. The raw material for forming a release agent layer was dried at 80 ° C for one minute, and then irradiated with ultraviolet rays (total amount of light: 250 mJ/cm ² ) to form a release agent layer 12 (thickness: 1.2 μm).

On the other hand, the second active energy ray curable compound (a2) is selected from the group consisting of diisopentaerythritol hexaacrylate, and 94 parts by mass based on the total mass of the solid. The second polyorganosiloxane (b2) is selected from the group consisting of polydimethyl methacrylate containing polyether acrylonitrile (made by BYK Chemical Co., Ltd., the product name is "BYK-3500", which accounts for the total mass percentage of solids. ] 1 part by mass. The second photopolymerization initiator (c2) is an α -aminoalkylphenol-based photopolymerization initiator (manufactured by BASF Corporation, the product name is "IRGACURE907", 2-methyl-1[4-(methylthio)). Phenyl]-2-morpholinylpropan-1-one, 5 parts by mass based on the total mass of the solid. The above material was dissolved in a mixed solvent of isopropyl alcohol/methyl ethyl ketone (mass ratio: 3/1) and diluted to 20% of the total mass of the solid content to obtain a raw material for forming a primer layer.

Next, a primer for forming a base material for forming a base material is applied onto the second surface 112 of the substrate 11. After the raw material for forming the undercoat layer is dried at 80 ° C for one minute, and irradiated with ultraviolet rays (total amount of light: 250 mJ/cm ² ), the undercoat layer 13 (thickness: 0.57 μm) is formed, that is, the release film is completed. 1.

(Examples 2 to 4)

The same procedure as described in the above Example 1 was carried out, except that the thickness of the undercoat layer 13 and the surface roughness of the back surface of the release film 1 were changed as shown in Table 1.

(Example 5)

The raw material for forming the undercoat layer in Example 1 was changed to the product which was diluted below in a solvent. The second active energy ray curable compound (a2) is selected from 95 parts by mass of diisopentaerythritol hexaacrylate (% by mass of the total solids). The second photopolymerization initiator (c2) is an α-aminoalkylphenol-based photopolymerization initiator (manufactured by BASF Corporation, the product name is "IRGACURE907", 2-methyl-1[4-(methylthio)). Phenyl]-2-morpholinylpropan-1-one, 5 parts by mass based on the total mass of the solid. The solvent was an isopropanol/methyl ethyl ketone mixed solvent (mass ratio: 3/1), and diluted to a solid content of 20% by mass to obtain a raw material for forming a base coat layer. Except for this change, the rest was produced in the same manner as described in the above Example 1.

(Example 6)

The same procedure as described in the above Example 1 was carried out except that the thickness of the release agent layer 12 and the surface roughness of the release agent layer 12 were changed as shown in Table 1.

(Example 7)

The substrate 11 is selected from a film formed by biaxially stretching polyethylene terephthalate (thickness: 31 μm, average roughness Ra _{1 of the} first surface 111: 29 nm, maximum protrusion height of the first surface 111) Rp ₁ : 257 nm, the average roughness Ra _{2 of the} second face 112 is 29 nm, and the maximum protrusion height Rp _{2 of the} second face 112 is 257 nm. Further, the thickness of the release agent layer 12 and the undercoat layer 13 and the surface roughness of the release layer 12 and the back surface of the release film 1 were changed as shown in Table 1. Except for this, the rest were produced in the same manner as described in the above Example 1.

(Example 8)

The thickness of the release agent layer 12 and the undercoat layer 13 and the surface roughness of the release agent layer 12 were changed as shown in Table 1. Except for this, the rest were produced in the same manner as described in the above Example 7.

(Comparative Example 1)

The undercoat layer 13 was not formed, and the surface roughness of the back surface of the release film 1 was changed as shown in Table 1. Except for this, the rest were produced in the same manner as described in the above Example 1.

(Comparative Example 2)

The same procedure as described in the above Example 1 was carried out, except that the thickness of the release agent layer 12 and the surface roughness of the release agent layer 12 were changed as shown in Table 1.

(Comparative Example 3)

The substrate 11 is selected from a film formed by biaxially stretching polyethylene terephthalate (thickness: 31 μm, average roughness Ra _{1 of the} first surface 111: 15 nm, maximum protrusion height of the first surface 111) Rp ₁ : 98 nm, the average roughness Ra _{2 of the} second face 112 is 15 nm, and the maximum protrusion height Rp _{2 of the} second face 112 is 98 nm. Further, the thickness of the release agent layer and the surface roughness of the release agent layer and the back surface of the release film were changed as shown in Table 1. Except for this, the rest were produced in the same manner as described in the above Example 1.

(Comparative Example 4)

100 parts by mass of a heat-curing additional reaction type 制造 [manufactured by Shin-Etsu Chemical Co., Ltd., product name "KS-847H") was diluted in a stupid. 2 parts by mass of platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., product name "CAT-PL-50T") is added and mixed (that is, heat-curing additional reaction type: the ratio of platinum catalyst is 100:2) After that, a coating having a solid content of 5.0% of the total mass was obtained. The coating was dried to a thickness of 1.0 micron. This coating is applied to the first side 111 of the substrate 11 on the average. Next, the release agent layer 12 was obtained by drying the coating at 140 ° C for 1 minute. Further, the surface roughness of the release agent layer 12 and the back surface of the release film 1 was changed as shown in Table 1. Except for this, the rest were produced in the same manner as described in the above Example 1.

The above results are summarized in Table 1.

Further, the thickness tests of the release agent layer 12 and the undercoat layer 13 of each of the examples and the comparative examples were measured using a reflection film thickness meter (manufactured by Filmetrics, Inc.).

Further, the following measurement methods were used for the average roughness value and the maximum protrusion height. First, glue the double-sided tape to the glass. Next, the release film 1 obtained in each of the examples and the comparative examples was attached to the double-sided tape, and the opposite side of the surface to be measured was faced to the double-sided tape. According to JIS B0601-1994, the surface roughness tester SV3000S4 (stylus type) manufactured by Mitsutoyo Co., Ltd. was used to test the average roughness value and the most Large protrusion height.

In addition, the ratio of the area of the projections having a height of 10 nm or more can be calculated from the image obtained by the light interference type surface shape observation device "WYKO-1100" (manufactured by Veeco Co., Ltd.). The observation condition is PSI mode, 50 times rate. The resulting image was an image of a surface shape of 91.2 microns by 119.8 microns. Further, the portion and other portions having a height of 10 nm or more are distinguished and binarized, and the ratio of the area occupied by the portion having a height of 10 nm or more and the other portions can be calculated. From this area ratio, the ratio of the area of the protrusions having a height of 10 nm or more can be calculated.

[2] Evaluation

The following is an evaluation of the release film 1 prepared as described above.

[2.1] Curability assessment

The release film 1 obtained in each of the examples and the comparative examples was ground to the release agent layer 12 with a weight of 1 kg/cm 2 of a polishing cloth (manufactured by Otsu Industrial Co., Ltd., BEMCOT AP-2) containing 3 ml of MEK. The surface is 10 times. Thereafter, the surface of the release agent layer 12 was visually observed, and the evaluation of the curability was performed by the following criteria.

A: The release agent layer 12 is not dissolved or peeled off.

B: The release agent layer 12 was partially dissolved.

C: The release agent layer 12 is completely dissolved or peeled off.

[2.2] Curl evaluation

The release film 1 obtained in each of the examples and the comparative examples was cut into a shape of 200 mm × 200 mm. Next, each of the cut release films 1 is laid flat on the glass surface with the release agent layer 12 facing upward. Next, a glass plate of 100 mm × 100 mm was placed at the center of the release agent layer 12 of each release film 1. The curl height of the side of the release film 1 was measured again. Next, the total height of the glass surface to the end of the curled release film 1 was determined. Classified by the following criteria.

A: The total is less than 50 mm.

B: The total is more than 50 mm but less than 100 mm.

C: The total is 100 mm or more.

[2.3] Obstructive assessment

The release film 1 obtained in each of the examples and the comparative examples was cut into a shape of 5000 mm long and 400 mm, and was crimped into a tubular shape. These release films 1 are wet at 40 degrees Celsius After 30 days of storage in an environment of 50%, the appearance of each release film 1 was visually observed and classified by the following criteria.

A: No change in appearance (no obstruction) after crimping into a tubular shape.

B: The release film 1 which is rolled into a tubular shape has a color difference in a part of the film (it is possible to use the release film 1 having a tendency to block).

C: The release film 1 rolled into a tubular shape has a large block of chromatic aberration (with clogging).

As the above criteria, when the clogging of the release film 1 occurs close to the front surface and the back surface of the release film 1, the delamination of the large-sized film 1 occurs, and the release film 1 sometimes fails to roll out normally.

[2.4] The amount of charge when rolled out

The release film 1 obtained in each of the examples and the comparative examples was cut into a shape of 5000 m in length and 400 mm in width, and was crimped into a tubular shape. These release films 1 were stored in an environment of 50 degrees Celsius humidity of 50 degrees Celsius for 30 days. Next, the amount of charge was measured at a speed of 50 meters per minute using "KSD-0103" manufactured by Kasuga Electric Co., Ltd. The measurement of the charge amount was performed immediately after the release film 1 was taken up, and was measured at 100 mm of the release film 1 per roll length of 500 meters.

A: The charge is less than 5 kV and less than 5 kV.

B: The charge amount is minus 10 kV or more and less than minus 5 kV, or greater than positive 5 kV but below positive 10 kV.

A: The charge is lower than minus 10 kV or higher than positive 10 kV.

[2.5] Evaluation of coating properties of ceramic slurry

100 parts by mass of barium titanate powder (manufactured by Sigma Chemical Industry Co., Ltd., product name "BT-03", BaTiO ₃ ), and a binder of 8 parts by mass of ethylene butyral (manufactured by Sekisui Chemical Co., Ltd., product name "Esurekku" B.K BM-2"], with 4 parts by mass of plasticizer, dioctyl phthalate [manufactured by Kanto Chemical Co., Ltd., product name "dioctyl phthalate deer grade 1"), added to 135 parts by mass Toluene/ethanol mixed solvent (mass ratio 6 to 4). These were placed in a ball mill and mixed and dispersed to prepare a ceramic slurry. The above ceramic slurry was applied by die coating to the outer surface of the release agent layer 12 of the release film 1 of each of the examples and the comparative examples, and the degree of application was such that the dried film was 1 μm thick and 250 mm. It is 10 meters wide and long. After the obtained coating layer was dried at 80 ° C for 1 minute, it was facilitated to produce a birth embryo sheet on the release film 1 . Next, the release film 1 of these manufactured birth embryo sheets was irradiated with a fluorescent lamp. The irradiation direction of the fluorescent lamp was irradiated toward the surface on which the release film 1 was attached, and the surface on which the green sheet was attached was visually observed. The coating properties of the ceramic slurry were evaluated by the following criteria.

A: There are no small holes in the raw embryo sheet.

B: 1 to 5 small holes can be seen on the green sheet.

C: More than 6 small holes can be seen on the green sheet.

[2.6] Assessment of poor recovery

The release film 1 obtained in each of the above Examples and Comparative Examples and the respective green sheets produced in the above [2.5] were cut into a shape of 110 mm × 110 mm, two sheets each. Next, the two release films 1 having the green sheets formed thereon are superposed on each other, and are aligned up and down in such a manner that the green sheets are in contact with the release film 1. Come again, at A pressure of 10 kg per square centimeter is applied in an environment of 23 degrees Celsius. Thereafter, each of the four corners of the release film formed by pressing the green sheet was cut by 5 mm. Upon completion, the green sheet is released from the bottom surface of the release film 1. At this time, it is visually observed whether or not the green sheet is attached to the bottom surface of the release film 1.

A: The green sheet was not attached to the bottom surface of the release film 1.

B: A green sheet of less than 50 square centimeters is attached to the bottom surface of the release film 1.

C: A green sheet of 50 cm 2 or more is attached to the bottom surface of the release film 1.

[2.7] Evaluation of the excision of raw embryonic sheets

The green sheet formed in the above [2.5] was released from the release film 1. At this time, it is evaluated whether the green sheets are normally released.

A: The raw embryonic sheet is not broken and smoothly slipped. There is no residual green sheet on the release agent layer 12.

B: The raw embryonic sheet is not broken, and some are somewhat slippery and slippery. There is no residual green sheet on the release agent layer 12.

C: When the green sheet is released, the embryonic sheet has a crack, or the green sheet cannot be separated.

[2.8] Evaluation of the number of recesses 1

The polyvinyl butyral resin was dissolved in a toluene/ethanol mixed solvent (mass ratio 6 to 4). Further, the obtained coating slurry was applied onto the release agent layer 12 of the release film 1 obtained in each of the examples and the comparative examples, and the coating thickness was dried to obtain Up to the 3 micron coating layer. Further, the obtained coating layer was dried at 80 ° C for 1 minute to form a polyvinyl butyral resin layer. Next, a polyester tape was attached to the specific surface of the polyvinyl butyral resin layer. Further, the release film 1 was released from the polyvinyl butyral resin layer, and the polyvinyl butyral resin layer was transferred onto a polyester tape. Then, the polyvinyl butyral resin layer was observed with a light-interfering surface observation apparatus "WYKO-1100" (manufactured by Veeco Co., Ltd.), and the surface was observed to be in contact with the release agent layer 12 of the release film 1. The observation condition was 50 times the PSI mode. The polyvinyl butyral resin layer was recorded in the range of 91.2 μm × 119.8 μm, and the number of recesses of 150 nm or more was printed on the surface shape of the release agent layer 12 of the release film 1 . The number of recesses was evaluated by the following criteria. Further, when a laminated ceramic capacitor is produced using a polyvinyl butyral resin layer (green sheet) classified under the following standard C, there is a problem that a short circuit is likely to occur due to a low withstand voltage.

A: The number of recesses is equal to zero.

B: The number of recesses is greater than 1 and less than 5.

C: The number of recesses is greater than 6.

[2.9] Evaluation of the number of recesses 2

The polyvinyl butyral resin was dissolved in a toluene/ethanol mixed solvent (mass ratio 6 to 4). The obtained coating slurry was applied to a 50 μm thick PET film, and the coating thickness was dried to obtain a coating layer of 3 μm. Further, the obtained coating layer was dried at 80 ° C for 1 minute to form a polyvinyl butyral resin layer. Further, this polyvinyl butyral resin layer and each embodiment The release film obtained in each of the comparative examples was attached to form a laminate, and the undercoat layer of the release film was brought into contact with the surface of the polyvinyl butyral resin. Each of the laminates was cut into a shape of 100 mm × 100 mm. Next, a pressure of 5 kg per square centimeter was applied to the laminate, and the surface shape on the undercoat layer of the release film 1 was transferred onto the polyvinyl butyral resin layer. Next, the release film 1 was released from the polyvinyl butyral resin layer. The number of concave portions of 150 nm or more printed on the surface of the undercoat layer of the release film 1 on the polyvinyl butyral resin layer was calculated. Specifically, the polyvinyl butyral resin layer was observed by a light interference type surface observation apparatus "WYKO-1100" (manufactured by Veeco Co., Ltd.), and the observation surface was in contact with the release agent layer 12 of the release film 1. surface. The observation condition was 50 times the PSI mode. The polyvinyl butyral resin layer was recorded in the range of 91.2 μm × 119.8 μm, and the number of recesses of 150 nm or more was printed by the surface shape on the undercoat layer 13 of the release film 1. These recesses are formed by transferring the surface shape on the undercoat layer 13 of the release film 1. The number of recesses was evaluated by the following criteria. Further, when a laminated ceramic capacitor is produced using a polyvinyl butyral resin layer (green sheet) classified under the following standard C, there is a problem that a short circuit is likely to occur due to a low withstand voltage.

A: The number of recesses is equal to zero.

B: The number of recesses is greater than 1 and less than 5.

C: The number of recesses is greater than 6.

The above results will be shown in Table 2.

Table 2

As seen from Table 2, the release film 1 of the present invention has excellent coatability and allows the formed green sheet to have excellent release property and smoothness of front and back surfaces. Further, the release film 1 of the present invention can effectively prevent the problem of occurrence of pinholes or uneven thickness on the formed green sheet. Further, the release film 1 of the present invention is less likely to be clogged when it is crimped into a tubular shape. Further, the release film 1 of the present invention can attain a low charge amount when it is taken out from the tubular shape. Moreover, the release film 1 of the present invention can also prevent the green sheet from being attached to the bottom surface of the release film 1. In contrast, the comparative examples did not yield these results.

This release film 1 for producing a green sheet has a substrate 11, a release agent layer 12, and a primer layer 13. The substrate 11 has a first surface 111 and a second surface 112. The release agent layer 12 is formed after the active energy ray is irradiated to cure the release agent coating layer. The release agent coating layer is coated with a release agent layer into a base material. Formed on the first side 111 of the plate 11. The raw material for forming a release agent layer contains the first active energy ray curable compound (a1) and the first polyorganosiloxane (b1). The undercoat layer 13 is formed by irradiating the cured undercoat layer with active energy rays. The undercoat layer is formed by applying a raw material for forming a bottom coat layer onto the second surface 112 of the substrate 11. The raw material for forming the undercoat layer contains the second active energy ray curable compound (a2). The outer surface 121 of the release agent layer 12 has an average roughness Ra2 of 8 nm or less, and the outer surface 121 of the release agent layer 12 has a maximum protrusion height Rp2 of 50 nm or less. The outer surface 131 of the undercoat layer 13 has an average roughness Ra3 of between 5 nm and 40 nm, and the outer surface 131 of the undercoat layer 13 has a maximum protrusion height Rp3 of between 60 nm and 500 nm. According to the present invention, it is possible to prevent the occurrence of pinholes or uneven thickness on the finished green sheet. Therefore, the present invention has industrial applicability.

1‧‧‧ release film

11‧‧‧Substrate

111‧‧‧The first side of the substrate

112‧‧‧ second side of the substrate

12‧‧‧ release agent layer

121‧‧‧The outer surface of the release agent layer

13‧‧‧Bottom coating

131‧‧‧The outer surface of the undercoat

Claims (2)

A release film for producing a green sheet, comprising: a substrate having a first surface and a second surface; and a release agent layer cured by a reactive energy ray after curing a release agent coating layer Forming, the release agent coating layer is formed by coating a raw material for forming a release agent layer on the first surface of the substrate, and the material for forming the release agent layer contains a first active energy ray curable a compound and a first polyorganosiloxane; and a bottom coating formed by curing the bottom coating layer by the active energy ray, the bottom coating layer being coated with a raw material for forming a bottom coating layer Formed on the second surface of the substrate, the bottom coating layer forming raw material contains a second active energy ray curable compound; wherein the outer surface of the release agent layer has an average roughness value of less than 8 nm, and the The outer surface of the release agent layer has a maximum protrusion height of 50 nm or less; wherein the outer surface of the bottom coat layer has an average roughness of between 5 nm and 40 nm, and the outer surface of the undercoat layer is the largest The height of the protrusion is between 60 nm and 500 nm. The release film of claim 1, wherein the raw material for forming the undercoat layer further comprises a second polyorganosiloxane.